Well cleaning apparatus



Allg 18, 1942. H. A. lvionlrcsoh/IERY l2,293,442

WELL CLEANING APPARATUS Filed May '7. 1940 www Patented Aug. 18, 1942IUNIT-E D S PATENT 0F51 2,293,442

WELL CLEANING-APPARATUS Hugh A. Montgomery,Houstcn, Tex.

Applcation'May 7, 1940, Serial No.333,7=38

1 Claim.

This invention relates to new and useful im provements in well cleaning.apparatus.

It has been found advantageous to introduce various solvents, acids, andother chemicals into well casings and/or tubings to reduce and eliminatethe deposition of parain. A common practice is to introduce a solvent orreagent into the well bore at intervalsto dissolve or clean outanyparaln which may have deposited on the wall of the well casing or thewell. tubing. However, this solvent or reagent has been introduced intothe upper part of the well and allowed to flow downwardly. Obviously, toproperly wet the wall of the well casing or tubing with the reagent, asuiucient quantity must be introduced to allow some to liow into the oilsands. This is very detrimental to the well and often causesV a well tocease flowing altogether.

One object, therefore, of this invention is to provide an improved wellcleaning apparatus, whereby thesolvent or reagent may be introduced intoa section or portion of the well below the upper end thereof.

Another object of the invention is to provide an improved well cleaningapparatus, whereby the solvent or reagent may be introduced in anydesirable .amount directly into the well stream owing through the welltubing, and whereby the amount and frequency of introduction of thesolvent or reagent may be positively and readily controlled.

A further object of the invention is to provide an improved wellcleaning apparatus which is simple in structure, and which may bereadily disconnected frorn the tubing string to allow the latter to bewithdrawn from the well bore.

Still another object of the invention is to provide an improved wellcleaning apparatus which may be attached to a section of ordinary tubingstring, thereby eliminating the necessity of special tools or operationsand reducing the cost of the apparatus.

A construction designed to carry out the invention will be hereinafterdescribed, together with other' features of the invention.

The invention will be more readily understood from a reading of thefollowing specication and by reference to the accompanying drawing, inwhich an example of the invention is shown, and wherein:

Figure 1 is a schematic View of a well cleaning device, constructed inaccordance with the invention, mounted on a tubing string in a wellbore,

Figure 2is a longitudinal sectional view,oshow ing the'structure of theconnecting member,

FigureiS. is Ya viewin. elevation taken atright angles to Figure 2, and

Figure Y4 is a horizontaL; cross-sectional View taken on theline 1 -lofFigure 3.

In the drawing, ther numeral I!! ,designates the tubing string whichislowered into a well bore or casing. An elongate valvebody II of blisterlike shape is Welded, or otherwise suitably `fastened, to the outside ofone tubingsection `I2 of the ,tubing string IB at any point at which itisl desired to introduce solvents or reagents, and a .check valve I3 ispositioned therein. Any desir-able type of check valve may be used inthe valve body. It has been found advantageous to use the valve andvalve bodyillustrated in the drawing. The body I I is. formed with asubstantially semi-circular cross-section, andhas its upper and lowerends rounded. The rounded ends greatly reduce thepossibilityof the bodyscatching on a collar or some other obstruction in the well bore as thetubing israised or lowered. A longitudinal bore I3' is provided in thevalve body. The lower portion of the bore I3 is. reduced and formed withinternal left-.hand screw. threads I. The threads I4 receive and engagethe left-hand screw-threaded lower end I5 of a string of relativelysmall tubing or pipe I6. The left-hand screw threads, connecting thepipe I6 to the valve body, allow the pipe to be disconnected byright-hand rotation and withdrawn from the well bore, leaving the tubingI0 free to be withdrawn.

A counterbore I1 extends downwardly from the lower end of the bore I3',and terminates at a point spaced from the lower end of the valve body.The upper end of the counterbore I1 carries internal screw threads I8for receiving an annular internally screw-threaded valve seat I9. Avalve ball 20 is conned Within the counterbore between the valve seat I9and a coil spring 2I positioned in the lower portion of the counterbore.Thus the valve ball is constantly urged upwardly by the spring 2I toengage the seat IS and shut off communication through the seat and thebore I3. Pressure acting downwardly through the valve I3 will unseat thevalve ball and allow uids to flow downwardly, while pressure actingupwardly upon the valve will only serve to seat the valve ball tighteragainst the seat I9.

A radial port 22 extends from one side of the counterbore Il at a pointbelow the valve ball to the outside wall of the tubing section I2, and

lformed of the usual sections or lengths 24, which lare coupled by meansof collars 25. The pipe nextends from the upper end of the valve I3, up'the well bore to a pump 26 situated at or ad- .jacent the top of thewell bore. Any suitable type or design of pump, such as a steam or gaspump, a motor pump, or a hand pump, may be used at the upper end of thepipe I6. If the `-well is being pumped, the pump 26 may be connected tothe usual pump jack so as to operate --with the latter. Also, ifdesired, a second check 'valve (not shown) may be placed in the pipe I6-at a point adjacent the pump 26 to protect the fapparatus in the eventthe valve I3 is held open Joy foreign matter entering between the ball20 rand the seat I9. The second check valve is not necessary to theoperation of the device, but merely furnishes an additional safeguardagainst the leakage of the well fluid upwardly through :the pipe I6. Inaddition, a pressure gauge (not shown) may be connected to the pipe I6to indicate the pressure present therewithin.

Suitable solvents or reagents may be pumped fdown the pipe I6, throughthe valve I3 and the :orice 23, into the Well stream flowing through`the tubing string I0. The solvent or reagent will Vlbe carried towardthe top of the well by the lowing well stream, and will loosen anddissolve Ythe paraffin deposits present on the inside wall of the tubingstring.

Manifestly, the apparatus as described hereinbefore, offers manyadvantages. The solvent or reagent uids used will remain standing in thepipe I6 at all times, due to the fact that it will not exert sufficientpressure to open the valve I3 and drain into the tubing section I2against the well pressure and the spring 2I. Under these conditions, asmuch or as little fluid as deemed suitable may be pumped through thepipe into the well stream. This allows the apparatus to be used underthe widely varying conditions encountered in diierent wells. Theinjection of the fluid is positive, due to the action of the pump 26,and is carried out in such a manner as to cause the fluid to be carriedupwardly by the well stream or flow. Obviously, the valve body II may beplaced at any desirable point in the tubing string IU, so that thetubing will be treated from any such point to the surface of the ground.

The device may be used to inject fluid solvents, acids, reagents, hotwater, steam, and other desirable fluids, into the tubing of an oil wellor any other type of well. The invention is not to be limited to usewith paraffin solvents.

As the amount of treating iiuid and the length of treatment usuallyvaries from well to well, no particular operating procedure may bestated. The device may be operated continuously or intermittently as theparticular well requires, Various changes, alterations and modificationsmay be made in the size, shape and arrangement of the herein describedelements, within the scope of the appended claim.

What I claim and desire to secure by Letters Patent is:

A cleaning apparatus for wells including a conductor formed with apassageway through which the well stream flows, and provided with aninlet communicating with the interior of the passageway, a hollowblister-like body having its marginal edges rounded and merging into theperiphery of the conductor and provided with a port communicating withsaid inlet of the conductor means detachably connected to the body forconveying a cleaning agent into the body and therethrough into the wellstream, said inlet being below the top of the well whereby the agentupon encountering the well stream will be carried upwardly by thestream, and said body being intimately welded at its margin to theperiphery of the conductor to prevent the escape of the cleaning agentthrough the joint between the body and conductor, and a check valve inand movable longitudinally of the body and located above the portthereof, to prevent the well stream from entering the cleaning agentconveying means.

HUGH A. MONTGOMERY.

